1. Field of the Invention
The invention pertains to a carbon nanotube signal modulator for reducing, eliminating, or enhancing the resonance interaction between photonic elements, and a photonic transmission device that may incorporate the signal modulator.
2. Description of Related Art
Electronic transistors are commonly fabricated on silicon wafers to make electronic computer chips and, unfortunately, have performance limitations that make them increasingly more expensive to manufacture to perform suitably as the performance requirements of computers increase. Photonic devices are under investigation as a potential solution to this problem—they are an advancement that takes advantage of the intrinsic properties of photons.
Photonic computing serves as an example application. Photonic computing uses photons of laser light instead of electrons as the basis for the computing element. As a result of ongoing efforts in this field, the art of computing has been working towards the development of a photonic signal modulator or “switch” that could be used as the basis for a photonic computing device. Some work has been focused on the development of a non-linear crystal capable of, for example, on/off modulation of a beam of photons. U.S. Pat. No. 5,093,802 teaches, for example, an optical computing method that uses interference patterns. And, a non-linear optics approach has also been investigated in order to make use of the optical properties of certain crystalline materials and modify the relative speed of the light. Existing electro-optical technologies, such as micro-electro-mechanical systems (MEMS), use tiny mechanical parts such as mirrors and thermo-optics technology derived from ink-jet technologies. These technologies have been used to create bubbles that can deflect light. Unfortunately, each of these attempts at producing a photonic signal modulator has uncovered problems that limit its use.
Synthesis of nanomaterials and construction of sophisticated nanodevices has uncovered physical phenomena and created opportunities in several technical areas. For example, a phenomenon of nanotechnology is that vibrational and electromagnetic (EM) frequencies can be substantially higher in the nano domain and, as a result, can be useful in communications and sensing applications. As device feature sizes decrease and bandwidth density pressure increases, nanomaterials and their associated wavelengths and resonant frequencies appear to have become increasingly more important. In turn, the extension of RF technology and practices into higher frequencies and smaller scales requires developing, for example, novel diode technology, as well as non-linear electronic elements that are capable of operating through harmonic interaction, amplification, and modulation at elevated speeds and efficiencies in the higher frequency ranges.
The physical dimensions and electron mobility associated with carbon nanotubes (CNTs) provide us with materials having properties that make them attractive for use in electronic devices that operate in the optical domain. For example, the integration of CNTs into conductive polymeric thin films and densely packed CNT arrays have produced a classical antenna-like response to incident light. See Wang et al., App. Phys. Lett (2004). In these nanotube “forest” arrays, the CNTs can be grown (i) vertically aligned to produce a “polarization effect” relating to their alignment and (ii) to the same length to produce a “length effect” and consequent “resonance” interaction.
The teachings provided herein represent an improvement over the current state-of-the-art. One of skill will appreciate that the only relevant experiments with CNTs have thus far have been limited to bulk CNT samples having largely overlapping field geometries, such that the performance of oriented CNT arrays has not been appreciated. Most importantly, however, the art will benefit highly from a functioning CNT signal modulator that is capable of reducing or eliminating the resonance interaction of photons within a CNT array.